A surge in the use of electric bicycles throughout the United States is prompting cities to revise regulations that restrict their use, including bans against riding them on sidewalks and trails.

The nation’s capital and other Washington-area jurisdictions are among those taking steps to modernize and streamline policies advocates say are outdated, set unrealistic restrictions and confuse riders of bikes that can be run on electric power as well as by pedaling.

“The number of bicyclists in the U.S. is growing, in part because of the rise of e-bikes, but it is difficult for people to know where they are allowed to ride them,” said Morgan Lommele, with the cycling advocacy group PeopleForBikes. “The laws are all over the place for electric bicycles.”

About half of U.S. states classify e-bikes as motor vehicles, requiring licensing, registration and even insurance — essentially making them illegal to ride, Lommele said. Others put pedal-assist e-bikes with speeds up to 20 mph in the same category as regular bicycles, allowing them to share the same road infrastructure.